Airflow Systems V410, Owner'S Manual

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A16
MOTOR WIRING GUIDE
(BRANCH CIRCUIT)
WIRING
To connect motor for proper voltage and rotation, refer to connection diagram on nameplate or inside terminal/conduit
box. If power factor correction capacitors are used for individual motor power factor correction, do not exceed maximum
recommended value.
All aspects of the installation must conform to the requirements of the NEC, including Article 430 (Motor Circuits and
Controllers), and all local codes. Wherever possible, each motor should be powered from a separate circuit of adequate
capacity to keep voltage drop to a minimum during starting and running. Increase wire size where motor is located a
distance from the power source. Wire size must be adequate to minimize voltage drop during starting and running. Refer to
Tables A and B for suggested wire sizes. Distances shown are one-way between source and load. Portable cords, if used,
should be as short as possible to minimize voltage drop. Long or inadequately sized cords, especially on hard starting
loads, can cause motor failure. Insulate and protect motor lead connections to prevent cut-through from sharp edges and
vibration. Tape wire nuts to prevent loosening. All electrical connections in system must be secure to prevent voltage drop
and localized heating.
Determine direction of rotation before connecting driven equipment to prevent damage. Remove shaft key if motor is to
be operated at no-load. On three phase motors, interchange any two line leads (not motor leads) to reverse rotation. On air
compressors, rotation of flywheel should direct air towards the cylinders. Look for rotational arrow on flywheel.
All motors must be securely and adequately grounded by wiring with a grounded, metal-clad raceway system, using a
separate ground bond wire connected to bare metal on the motor frame, or other suitable means. Refer to NEC Article 250
(Grounding) for additional information.
Explosion-proof motors incorporating over temperature thermostats should be controlled with a magnetic starter. The
thermostat circuit must be wired in series with the holding coil circuit, as shown on tag or nameplate on motor, to remove
power from the starter coil if motor overheats.
TABLE A - MINIMUM WIRE SIZES FOR THREE-PHASE MOTORS
MOTOR 25 FT TO 50 FT 100 FEET 150 FT TO 200 FT
HP 200V 230V 460V 200V 230V 460V 200V 230V 460V
1/8 14(18)
*
14(18)* 14(18)* 14(18)
*
14(18)* 14(18)* 14(16)
*
14(18)* 14(18)*
1/6 14(18)
*
14(18)* 14(18)* 14(18)
*
14(18)* 14(18)* 14(16)
*
14(16)* 14(18)*
1/4 14(18)
*
14(18)* 14(18)* 14(16)
*
14(18)* 14(18)* 14 14 14(18)*
1/3 14(18)
*
14(18)* 14(18)* 14(16)
*
14(16)* 14(18)* 12 14 14(18)*
1/2 14(16)
*
14(18)* 14(18)* 14 14 14(18)* 10 12 14(18)*
3/4 14 14(16)* 14(18)* 12 14 14(18)* 8 10 14(16)*
1 14 14(16)* 14(18)* 10 12 14(18)* 8 10 14
1½ 12 14 14(18)* 10 10 14(16)* 6 8 14
2 12 12 14(18)* 8 10 14(16)* 6 6 12
3 10 12 14(18)* 8 8 14 4 6 12
[*]Type S, SO, SJ, SJO, etc. flexible cable wire sizes. See NEC Article 400 for ampacity
.
Note: Above wire sizes based on approximate 5% voltage drop during starting; copper conductors; and 75°C type TH, THW, RH, RHW, etc.
insulation. For aluminum wire, increase two wire size steps minimum. See NEC Article 310 for ampacities of aluminum conductors and 60°C
type RUW, T, etc. insulation
.
TABLE B - MINIMUM WIRE SIZES FOR SINGLE-PHASE MOTORS
MOT0R 25 FT 50 FT 100 FT 150 FT 200 FT